Charging A Chargeable Power Supply of A Near Field Communication (NFC) Enabled Device from A Radio Frequency (RF) Signal Inductively Coupled Onto A Magnetic Field

ABSTRACT

A NFC communicator or NFC communications enabled device has a data store to store data, a coupler to couple inductively with the magnetic field of a radio frequency signal and a signal generator to supply a radio frequency signal to the coupler. A modulator is provided to modulate a radio frequency signal in accordance with data and a demodulator is provided to extract data from a modulated radio frequency signal inductively coupled to the coupler. A controller enables the NFC communicator or NFC communications enabled device both to initiate near field radio frequency communication with another near field RF communicator and to respond to near field radio frequency communication initiated by another near field RF communicator. The NFC communicator or NFC communications enabled device also has a power deriver that derives power from a radio frequency signal inductively coupled to the coupler to charge a chargeable power supply.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a CONTINUATION of U.S. patent application No.11/795,434, filed Jul. 17, 2007, which is the National Stage ofInternational Application No. PCT/GB06/00195, filed Jan. 19, 2006, whichclaims priority to United Kingdom Application No. 0501115.0. Theentirety of each of the above referenced Applications is herebyincorporated by reference for all purposes.

FIELD OF DISCLOSURE

This invention relates to NFC communicators and devices comprising NFCcommunicators.

BACKGROUND

Near field RF (radio frequency) communication requires an antenna of onenear field RF communicator to be present within the alternating magneticfield (H field) generated by the antenna of another near field RFcommunicator by transmission of an RF signal (for example a 13.56 MegaHertz signal) to enable the magnetic field (H field) of the RF signal tobe inductively coupled between the communicators. The RF signal may bemodulated to enable communication of control and/or other data. Rangesof up to several centimetres (generally a maximum of 1 metre) are commonfor near field RF communicators.

Near field communication may be referred to as near-field RFID (RadioFrequency Identification) or near-field communication. NFC communicatorsare a type of near field RF communicator that is capable of bothinitiating a near field RF communication (through transmission orgeneration of an alternating magnetic field) with another near field RFcommunicator and of responding to initiation of a near field RFcommunicator” includes not only NFC communicators but also initiatingnear field RF communicators such as RFID transceivers or readers thatare capable of initiating a near field RF communication but notresponding to initiation of a near field RF communication by anothernear field RF communicator and responding near field RF communicatorssuch as RFID transponders or tags that are capable of responding toinitiation of a near field RF communication by another near field RFcommunicator but not of initiating a near field RF communication withanother near field RF communicator. Hence NFC communicators can act asboth RFID transceivers and RFID transponders and are able to communicatewith other NFC communicators, RFID transceivers and RFID transponders.

Examples of near field RF communicators are defined in various standardsfor example ISO/TEC 18092, ISO/IEC 14443, ISO/IEC 15693 ISO/IEC 21481.

NFC communicators may be provided as standalone or discrete devices ormay be incorporated within or coupled to larger electrical devices orhost devices (referred to below as NFC communications enabled devices)to enable those devices to communicate by the near field with other nearfield RF communicators or devices incorporating or coupled to such nearfield RF communicators. When incorporated within a larger device orhost, a NFC communicator may be a discrete entity or may be provided byfunctionality within the larger device or host. Examples of such largerdevices or host devices are, for example, mobile telephones, portablecomputing devices (such as personal digital assistants, notebooks,lap-tops), other computing devices such as personal or desk topcomputers, computer peripherals such as printers, or other electricaldevices such as portable audio and/or video players such as MP3 players,IPODs®, CD players, DVD players.

NFC communicators and host devices of course require a power supply tofunction. Where an NFC communicator or host device incorporating orcoupled to an NFC communicator is powered by a chargeable power supplysuch as a rechargeable battery, then maintenance of a sufficient powersupply is of prime importance to the functioning of both the host deviceand the NFC communicator, particularly where the NFC communicator orhost device is being used in circumstances in which charging of thebattery using a mains charging unit is not possible, for example becausethe user of the NFC communicator or host device does not have the mainsrecharging unit with them or is in a location without access to a mainspower supply point. These power supply issues may be exacerbated for ahost device because the NFC communicator may place an additional drainon the chargeable power supply of the host device. Additionally absenceof suitable power supply may prevent or interrupt near field RFcommunication between one NFC communicator and another near field RFcommunicator. Depending on the application of such communication thiscould result in a failure to complete a required function or action, forexample, a failure to obtain access to a location, refusal of a ticketto travel, inability to purchase goods or transfer data or informationbetween electrical devices.

BRIEF SUMMARY

In one aspect, the present invention provides an NFC communicator or anNFC communications enabled device such as an a host device incorporatingNFC functionality (either by way of a discrete NFC communicatorincorporated within or coupled or attached to the host device or by wayof NFC functionality provided as part of, for example integrated with,the other functionality of the host device) which has or is associatedwith a chargeable power supply and has a power deriver which is operableto charge the chargeable power supply from an RF signal inductivelycoupled to the NFC communications enabled device or NFC communicatorwhen the NFC communications enabled device or NFC communicator is in thenear field of that RF signal. The RF signal may be provided by anotherNFC communicator or NFC communications enabled device or other nearfield RF communicator such as an RFID reader or an RFID tag, if the RFIDtag can provide sufficient power.

An NFC communications enabled device or NFC communicator embodying theinvention may thus charge a chargeable power supply by near field RFcommunication and/or enable another near field RF communicator orcommunications enabled device embodying the invention to charge itschargeable power supply by near field RF communication, thereby enablingthe NFC communications enabled device or NFC communicator to functioneven in circumstances where the chargeable power supply or one of anumber of available power supplies has been drained or has only a smallamount of power available and the user is not able to access a mainspower supply to charge up the chargeable power supply. The receivedpower may be used for some or all of the NFC communicator functionalityand/or any host device functionality.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

Embodiments of the present invention will now be described, by way ofexample, with reference to the accompanying drawings, in which:

FIG. 1 shows a representational diagram illustrating use of one NFCcommunications enabled device to charge a chargeable power supply ofanother NFC communications enabled device;

FIG. 2 shows a functional block diagram of an NFC communications enableddevice;

FIG. 3 shows a functional block diagram of an NFC communicatorillustrating one example of a power deriver that may be used to derivepower to charge a chargeable power supply;

FIG. 4 shows a functional block diagram illustrating communicationbetween the NFC communicator shown in FIG. 3 and another NFCcommunicator;

FIG. 5 shows a functional block diagram illustrating another example ofan NFC communicator according to the present invention;

FIGS. 6 to 8 show diagrammatic representations of different examples ofone NFC communications enabled device being used to charge a powersupply of another NFC communications enabled device; and

FIG. 9 shows a flowchart for illustrating use of an NFC communicationsenabled device such as a mobile telephone to obtain a ticket and then togain entry through an access gate controlled by that ticket.

With reference to the drawings in general, it should be understood thatany functional block diagrams are intended simply to show thefunctionality that exists within the device and should not be taken toimply that each block shown in the functional block diagram isnecessarily a discrete or separate entity. The functionality provided bya block may be discrete or may be dispersed throughout the device orthroughout a part of the device. In addition, the functionality mayincorporate, where appropriate, hard-wired elements, software elementsor firmware elements or any combination of these. The NFC communicatormay be provided wholly or partially as an integrated circuit orcollections of integrated circuits.

DETAILED DESCRIPTION

Referring now specifically to FIG. 1, there is shown a representationaldiagram illustrating use of one NFC communications enabled device tocharge a chargeable power supply of another NFC communications enableddevice. In FIG. 1 the representations of the NFC communications enableddevices have been show partly cut-away and the functionality provided bythe NFC communications enabled devices illustrated by way of afunctional block diagram within the NFC communications enabled device.

As shown in FIG. 1, one NFC communications enabled device comprises amobile telephone (cellphone) 1 and the other NFC communications enableddevice comprises a portable computer 2 such as a notebook or laptopcomputer.

The mobile telephone 1 has the usual features of a. mobile telephoneincluding mobile telephone functionality 10 (in the foul' of, usually, aprogrammed controller, generally a processor or microprocessor withassociated memory or data storage, for controlling operation of themobile telephone in combination with a SIM card), an antenna 18 forenabling connection to a mobile telecommunications network, and a userinterface 3 with a display 4, a keypad 5, a microphone 6 for receivinguser voice input and a loudspeaker 7 for outputting received audio tothe user. The mobile telephone also has a chargeable battery 11 coupledto a charging socket 12 via which a mains adapter (not shown) may beconnected to enable charging of the battery 11. The mobile telephone 1may have an alternative or additional power supply (not shown), forexample a reserve battery or emergency battery.

Similarly the portable computer 2 has the usual features of a portablecomputer including portable computer functionality 20 in the form ofusually, a processor with associated memory in the form of ROM, RAMand/or hard disk drive, one or more removable media drives such as afloppy disk drive and/or a CDROM or DVD drive, and possibly acommunications device for enabling the portable computer to connect to anetwork such as the Internet. The portable computer 2 also includes auser interface 21 including a display 22, a keyboard 23 and a pointingdevice, as shown a touchpad 24. The portable computer 2 also has achargeable battery 25 coupled to a charging socket 26 via which a mainsadapter (not shown) may be connected to enable charging of the battery25.

In addition, as shown in FIG. 1, the NFC communications enabled devices1 and 2 have an NFC communicator 15 and 30, respectively. As shown, theNFC communicators 15 and 30 are incorporated within the larger devicesand, as with the other functional blocks, may be discrete entitieswithin the host devices or may be provided by features dispersedthroughout or integrated within the host device or a part of the hostdevice.

Each NFC communicator 15 and 30 comprises NFC operational components 16and 31, respectively, for, as will be described below, enabling controlof the NFC functionality and generation, modulation and demodulation ofan RF signal. Each NFC communicator 15 and 30 also comprises a coupler17 and 32, respectively, comprising an inductor or coil in the form of arespective antenna 18 and 33. The couplers 17 and 32 enable analternating magnetic field (H field) generated by the antenna of onenear field communicator 15 (or 30) by transmission of an RF signal (forexample a 13.56 Mega Hertz signal) to be inductively coupled to theantenna of the other near field communicator 30 (or 15) when thatantenna is within the near field of the RF signal generated by the onenear field communicator 15 (or 30).

The NFC communicators 15 and 30 are coupled to the mobile telephone andportable computer functionality 10 and 20, respectively, to enable dataand/or control commands to be sent between the NFC communicator and thehost device and to enable user input to the NFC communicator.Communication between the user interface 3 or 21 and the NFCcommunicator 15 or 30 is via the host device functionality 11 or 20,respectively. In addition, each of the NFC communicators 15 and 30 iscoupled to their respective batteries 11 and 25 of their respective hostdevices 1 and 2 so that each NFC communicator is powered by thechargeable power supply of its host device. Alternatively oradditionally the NFC communicators 15 and 30 may be connected to theirown chargeable power supplies (not shown).

Each NFC communicator 15 and 30 also comprises a power deriver 19 and34, respectively, coupled between their respective couplers 17 and 32and their respective batteries 11 and 25 for, when the coupler 17 or 32is in the near field range of an antenna transmitting an RF signal,charging the battery 11 or 25 using a charging current or voltagederived from the inductive coupling to the coupler 17 or 32 of thealternating magnetic field (H field) generated by that RF signal.Additionally or alternatively the power deriver 19 and 34 may be coupledto additional power supplies within the host device or specific to theNFC communicators 15 and 30, for example a button cell battery, othersmall battery or capacitor.

Charging of a chargeable power supply of an NFC communications enableddevice may, for example, be initiated in response to user input to theuser interface (3 or 21 in FIG. 1) of the NFC communications enableddevice that requires charging, For example, when a user discovers thattheir NFC communications enabled device is low on power, then the usercan bring that NFC communications enabled device into the near fieldrange of another NFC communications enabled device that is not low onpower to enable the power deriver to charge up the chargeable powersupply. Thus in the scenario shown in FIG. 1, if a user discovers thattheir NFC communications enabled mobile telephone 1 is so low on powerthat they cannot make a call and they are without their mobile telephonecharging unit or have no access to a mains power outlet, they can usetheir NFC communications enabled portable computer 2 to charge up themobile telephone battery. Conversely, if the user discovers that theirNFC communications enabled portable computer 2 is low on power and theyare without their portable computer charging unit or have no access to amains power outlet, they can use their NFC communications enabled mobiletelephone 1 to charge up the portable computer battery.

As another possibility, charging may occur automatically when an NFCcommunications enabled device with a battery which is not fully chargedis in the near field of a suitable RF signal. For example, when thebattery is low, the NFC communicator 15 may be operable to couple to anynear field RF signal and through the power deriver 19, derive power fromthat near field RF signal.

As another possibility, charging may occur under the control of at leastone of the host device functionality and the NFC operational componentsof at least one of the NFC communications enabled device being chargedand the NFC communications enabled device providing the charge. As anexample, the NFC operational components (16 or 31) of the NFCcommunications enabled device to be charged (1 or 2) may allow chargingto occur only when that RF signal is not being used to communicatecontrol or other data or when specific permission has been received fromthe NFC communications enabled device providing the RF signal from whichcharge is to be derived so that one user may not, without authorization,charge their NFC communications enabled device using somebody else's NFCcommunications enabled device. Users with multiple NFC communicationsenabled devices may also be able to set those devices such that chargingis automatic when one device begins to get low on battery, tor examplein FIG. 1 settings on the portable computer 2 may be set by the user toprovide power to the mobile telephone 1 whenever the mobile telephonebattery requires charging.

It will be appreciated that FIG. 1 shows only examples of types of hostdevices. A host device may be another type of electrical device such asa personal digital assistant (PDA), other portable electrical devicesuch as a portable audio and/or video player such as an MP3 player, anIPOD®, CD player, DVD player or other electrical device.

Also, rather than being incorporated within the host device, the NFCcommunicator 15 or 30 may be associated with the host device, forexample by a wired or wireless coupling that is capable of powertransfer. In such a case, a housing of the NFC communicator may bephysically separate from or may be attached to the housing of the hostdevice; in the later case, the attachment may be permanent once made orthe NFC communicator may be removable. For example, the NFC communicatormay be housed within: a housing attachable to another device; a housingportion, such as a fascia of the NFC communications enabled de-vice oranother device; an access card; or may have a housing shaped orconfigured to look like a smart card. For example an NFC communicatormay be coupled to a larger device by way of a communications link suchas, for example, a USB link, or may be provided as a card (for example aPCMCIA card or a card that looks like a smart card) which can bereceived in an appropriate slot of the larger or host device.

In addition, one or both of the NFC communications enabled devices maybe a standalone NFC communicator, that is it may have no functionalitybeyond its NFC communications functionality.

FIG. 2 shows a functional block diagram of an NFC communications enableddevice 100 in accordance with the invention to illustrate in greaterdetail one way in which the NFC operational components of an NFCcommunications enabled device embodying the invention may beimplemented.

In this example, the NFC communications enabled device 100 comprises anNFC communicator 100 a having NFC operational components 101, aninductive coupler 102 and a power deriver 103 coupled between thecoupler 102 and a chargeable power supply 104 chargeable by the powerderiver 103. The NFC communications enabled device 100 may or may notalso have or be capable of being connected or coupled with at least oneof other functionality 105 (for example functionality of a host devicesuch as described above) and a user interface 106.

In the example shown in FIG. 2, the coupler 102 comprises a seriesconnection to earth (ground) of a capacitor 113 and an inductor 112. Asanother possibility a parallel circuit configuration may be used, oneexample of which will be described below with reference to FIG. 3. Theexact design of the inductor and inductive coupler will depend on thefunctionality, range and emission standard compliance requirements, plusthe environment within which the NFC communications enabled device 100is designed to operate.

The NFC operational components 101 comprise a controller 107 forcontrolling overall operation of the NFC communicator. The controller107 is coupled to a data store 108 for storing data (information and/orcontrol data) to be transmitted from and/or data received by the NFCcommunications enabled device. The controller 107 may be amicroprocessor, for example a RISC processor or other microprocessor ora state machine. Program instructions for programming the controllerand/or control data for communication to another near field RFcommunicator may be stored in an internal memory of the controllerand/or the data store.

The NFC operational components 101 also comprise a demodulator 114coupled between the coupler 102 and the controller 107 for demodulatinga modulated RF signal inductively coupled to the coupler 102 fromanother near field RF communicator in near field range and for supplyingthe thus extracted data to the controller 107 for processing.

In addition the NFC operational components 101 include components forenabling modulation of an RF signal to enable data to be communicated toanother near field RF communicator in near field range of the NFCcommunicator 100 a.

As shown in FIG. 2, the NFC operational components 101 comprise amodulator 110 coupled via a driver 111 to the coupler 102. The modulator110 may, for example, switch a transistor (for example a FET) coupledacross the inductor 112 on and off in accordance with the data suppliedby the controller 107, thereby modulating the load on the inductor 112and thus an RF signal supplied by the NFC communicator in accordancewith that data. Alternatively or additionally modulation of an RF signalmay be provided by sine synthesis (which for example may generate a PDM(Pulse Density Modulation) signal to the driver 111). As a furtheralternative the NFC communicator may comprise an emulator intended toenable interference or simulated load modulation of a received RF signalas described in greater detail in WO 2005/045744, the whole contents ofwhich are hereby incorporated by reference. In this latter case, thesignal generator will be replaced by the circuitry described in WO2005/045744 that enables interference or simulated load modulation of areceived RF signal.

The NFC communicator 100 a may operate in an initiator mode or a targetmode, dependent on the mode to which the NFC communicator is set. Themode may be determined by the controller 107 or may be determined independence on the nature of a received near field RF signal. When ininitiator mode, an NFC communicator initiates communications with anycompatible near field RF communicator capable of responding to theinitiator mode NFC communicator (for example an NFC communicator intarget mode or an RFID tag or transponder) that is in its near fieldrange, while when in target mode an NFC communicator waits for acommunication from a compatible near field RF communicator that iscapable of initiating near field communication a (for example an NFCcommunicator in initiator mode or an RFID reader or transceiver). Asthus used, compatible means operable at the same frequency and inaccordance with the same protocols, for example in accordance with theprotocols set out in various standards such as ISO/IEC 18092, ISOJEC21481, ISO/IEC 14443 and ISO/IEC 15693.

When in initiator or target mode, the NFC communicator may communicatein accordance with an active or passive protocol. When using an activeprotocol the initiating NFC communicator will transmit an RF field andfollowing completion of its data communication turn off its RF field.The responding RF communicator (target) will then transmit its own RFfield and data before again turning off the RF field and so on. Whenusing a passive protocol the NFC communicator (initiator) will transmitand maintain its RF field throughout the entire communication sequence.The protocol used will depend on instructions received faun thecontroller 107 and the response received from a responding RFcommunicator.

When an NFC communicator as shown in FIG. 2 is in initiator mode (andtherefore is transmitting an RF signal), the controller 107 isconfigured to control the modulator and signal generator to transmit amodulated or un-modulated RF signal through driver 111. Modulation willbe in accordance with at least one of data held in data store 108 andcontrol data held within controller 107. The data communicated willdepend upon the communications protocol tinder which the NFCcommunicator is operating and the data stored in the data store 108. Forexample, the initial data communicated may be a wake-up instruction (forexample REQA) to any receptive device (for example an NFC communicatorin target mode or an RFID transponder) in near field range.

When an NFC communicator as shown in FIG. 3 is operating in target mode,it will wait to receive an RF signal from an initiator mode NFCcommunicator or RFID reader through the coupler 102. On receipt of suchan RF signal, the demodulator 114 will demodulate the RF signal toextract any data carried by the RF signal and will supply a digital datasignal to the controller 107. The demodulated signal may be, forexample, a wake-up instruction (for example REQA). The controller 107will respond to such received data in accordance with its programmingand/or data stored in the data store 108. Response in target mode may bethrough load modulation of the received RF signal (through modulation ofload on inductor 112). Alternatively certain NFC communicators mayrespond through interference with the received RF signal oralternatively through transmission of a modulated RF signal (asdescribed above).

The initial response of the controller 107 in the target mode to a wakeup request may be to modulate the RF signal with an ATQA response orequivalent. Thereafter data communication between the initiator andtarget will occur by modulation of the RF signal or signals inaccordance with the communications protocol under which thecommunicating devices operate or have agreed to operate where there ismore then one possibility. Any suitable form of modulation scheme may beused, for example FSK (Frequency Shift Key) modulation, PSK (Phase ShiftKey) modulation, PDM (Pulse Density Modulation), amplitude modulation,or load modulation.

As set out above, the NFC communications enabled device shown in FIG. 2has its own chargeable power supply 104 (which may be part of the NFCcommunicator or may be the power supply of a host device) and when thatchargeable power supply 104 is drained or is not fully charged, thepower deriver 103 of the NFC communications enabled device may derivepower from any suitable RF signal within near field range of the coupler102 so as to charge the chargeable power supply 104. A suitable RFsignal may be for example an RF signal supplied by another NFCcommunications enabled device or near field RF communicator (for examplean RFID reader or an RFID tag if the tag is capable of supplyingsufficient power).

As will be appreciated from the above, the controller 107 is operable tocontrol the NFC communications process to, for example, ensure that theNFC communicator operates in compliance with the appropriatecommunications protocol(s) and to control the timing (using its ownclock where appropriate), manner and mode of operation of the NFCcommunicator. The controller 107 is also operable to controlcommunication with any host device, where required. Depending upon thecircumstances, a change in functionality of the NFC communicator or ofany host device may arise as a result of communication with another NFCcommunications enabled device. Alternatively communication may result ina change to the data stored in either one or both of the data store 108and controller 107.

The functionality of the controller 107 is shown in FIG. 2 as beingentirely within the NFC communicator. As other possibilities, thefunctionality of the controller 107 may be entirely within any hostdevice controller or distributed between the NFC communicator and thehost device. As a further possibility, certain control functionality mayreside within a separate unit which is attachable or removable oralternatively only used for certain transactions, for example a securitydevice or ESD device which may only be used for payment transactions.Where the functionality of the controller 107 is within a separate unitor within any host device, then instead of the controller 107 the NFCcommunicator will have a coupling, possibly including an appropriateinterface, to that controller.

As shown in FIGS. 1 and 2, the data store 108 comprises a memory withinthe NFC communicator. As another possibility, the data store 108 may becomprised within any host device or shared or co-located memory deviceor data storage means. For example the data store may reside within thehost device and all data may be centrally held within such host device.Alternatively data may be stored both within the NFC communicator (forexample data relevant to operation of the NFC functionality) and withina memory (not shown) within the host device (for example data relevantto the operation characteristics of the host device). The data storagemeans may be read only or may be read/write, depending upon whether datais to be written to as well as read from the data store.

FIG. 3 shows a functional block diagram of an NFC communicator toillustrate one example of a power deriver that may be used in an NFCcommunications enabled device embodying the invention, The power deriver103 shown in FIG. 2 may be of the type shown in FIG. 3.

The NFC communicator 200 shown in FIG. 3 again has an inductive coupler163 coupled to NFC operational components 300 (shown as a singlefunctional block 300 in FIG. 3) and to a power deriver 164 which iscoupled to a chargeable power supply 159 that, although not shown inFIG. 3, is coupled to provide power to the various components of the NFCcommunicator. Although not shown in FIG. 3, the NFC communicator 200 may(or may not) have other functionality and a user interface as shown inFIG. 2. As another possibility the other functionality and/or userinterface may be provided by a host device incorporating the NFCcommunicator or to which the NFC communicator is attached or coupled.The power supply 159 may comprise a power supply of the NFCcommunicator, the host device or both. The NFC operational components300 may be as described above with reference FIG. 2.

In the example shown in FIG. 3, the coupler has a parallel circuitconfiguration and comprises a parallel coupling of an inductor 207 inthe form of an RF antenna and a capacitor 152 with one end of theparallel coupling being coupled to the power deriver 164 by a firstseries connection of a capacitor C1 and a resistor R1 and the other endof the parallel coupling being coupled to the power deriver 164 by asecond series connection of a capacitor C2 and a resistor R2. As anotherpossibility a series type inductive coupler such as that shown in FIG. 2may be used. As set out above, the exact design of the inductor andinductive coupler will depend on the functionality, range and emissionstandard compliance requirements, plus the environment within which theNFC communications enabled device is designed to operate.

As shown in FIG. 3, the power deriver 164 comprises a rectifier 154 forgenerating a rectified power output (represented by arrow 160) from anRF signal coupled to the coupler 163 and a charging unit 157 forgenerating a charging power output (represented by arrow 161) from therectified output.

The rectifier 154 may be any suitable thou of rectifier, for example abridge rectifier, half-wave rectifier, or voltage doubler. Where the NFCcommunicator or NFC communication enabled device is comprised within anintegrated circuit or series of integrated circuits, the rectifier 154may advantageously be produced by an on-chip rectification circuitfunctioning as a bridge rectifier.

The charging unit 157 is desirably configured to control the chargingprocess so as to achieve charging of the chargeable power supply 159 inthe most efficient manner possible and to optimize the power transferaccording to the charging requirements of the chargeable power supply159.

The chargeable power supply 159 is shown in FIG. 3 as a battery and mayconsist of one or more cells. The chargeable power supply 159 mayhowever be of any form that can be charged or re-charged via electricalpower, such as for example a capacitor, button cell, battery.

FIG. 3 shows a functional block diagram of one suitable form of chargingunit 157. As shown in FIG. 3, the charging unit 157 comprises a switchedmode power supply unit (SM PSU) 251 controlled by power supply unit(PSU) controller 250 via signal line 252. The power supply controller250 may be a microcontroller, microprocessor, digital signal processoror state machine, for example.

As set out above, the fact that the PSU controller 250 is shown as aseparate functional block does not necessarily mean that it is aseparate entity, for example the power supply unit (PSU) controller 250may be separate from or included within any other controllerfunctionality within the NFC communicator 200 for example within thecontroller 107 shown in FIG. 2.

The rectified output voltage node 156 of the rectifier 154 is coupled toan input of the SM PSU 251. This coupling may be via an inductor 257 tomake power-factor corrections in order to increase power transferefficiency as is well known to persons skilled in the art. If present,then, for a typical RF input frequency of 13.56 MHz, the inductor 257will typically have a value of between 10-100 micro Henries. It isadvantageous, but not essential, to include the inductor 257. As isstandard practice for power derivation and supply, a capacitor 258 iscoupled across the input to the SM PSU 251 to smooth the rectified ACcycles.

The PSU controller 250 is configured to monitor the input voltage 254,input current 253, output voltage 256 and output current 255 of the SMPSU 251 to ensure matching of the source and input impedances andtherefore to ensure maximal power transfer. The source impedanceincludes all impedances in the power coupling path including the effectsof mutual inductance from coupling, between the inductive coupler 163and another inductive coupler presented at the input of the SM PSU 251while the input impedance of the SM PSU 251 is affected by the impedanceof the chargeable power supply 159 and any circuit coupled to thechargeable power supply 159.

In addition to impedance matching, the PSU controller 250 is, of course,operable to control the SM PSU 151 such that the values of outputvoltage 256 and output current 255 are appropriate to achieve correctcharging of the chargeable power supply 159.

Although FIG. 3 shows the use of a switched mode power supply unit, anysuitable form of charging unit 157 may be used in an NFC communicator orNFC communications enabled device embodying the invention, for example alinear control regulator may be used.

During operation of the NFC communicator shown in FIG. 3, a power supplyfor the NFC communicator and possibly any host device may be derivedfrom the chargeable power supply 159 or from the output of the rectifier154 or the output of the charging circuit 157 or any combination ofthese. Using power derived by the power deriver 164 directly to powerparts of the NFC communicator and/or any host device where possiblerather than relying on the chargeable power supply 159 of course avoidsdraining the chargeable power supply.

FIG. 4 shows a functional block diagram for assisting in fartherexplaining examples of how NFC communicator or NFC communicationsenabled device 200 may derive power from another near field RFcommunicator 400.

The power deriving NFC communicator 200 shown in. FIG. 4 is as describedabove with reference to FIGS. 2 and 3 and the same numbering is usedwhere relevant. The power providing near field RF communicator 400 maybe an NFC communicator or NFC communications enabled device similar tothat described above in relation to FIGS. 2 and 3 or may compriseanother form of near field RF communicator which is capable ofcommunicating via inductive coupling, with the first NFC communicator200. The second power providing near field RF communicator may be anRFID transceiver when the power deriving NFC communicator is operatingin target mode and could possibly be an RFID tag when the power derivingNFC communicator is operating in initiator mode, if the RFID tag canprovide sufficient power.

As described above, each of the communicators shown in FIG. 4 may or maynot have additional functionality, that is the functionality may beprovided within or attached to a host device such as those describedabove. In the latter case, functionalities such as processing powerand/or data storage may be shared with the host device.

The near field RF communicator 400 comprises, in the example shown inFIG. 4, an NFC communicator having NFC operational components 450 and aninductive coupler 462 shown for simplicity simply as a block. Theinductive coupler 462 is a tuned circuit comprising a capacitor and aninductor formed as an antenna and may have any of the configurationsdiscussed above with reference to FIGS. 2 and 3 the exact design of theinductor and inductive coupler depending on the functionality, range andemission standard compliance requirements, plus the environment withinwhich the RF communicator 400 is designed to operate.

The near field RF communicator 400 has its own power supply (not shown).This power supply may be specific to the near field RF communicator 400or may form part of a host device and may be, for example a battery ormains supply. This power supply powers the operation of the near fieldRF communicator 400 when, for example, it acts as an initiator, that iswhen the NFC operational components 450 generate an RF signal which isfed to the inductive coupler 462.

When the coupler 163 of the first NFC communicator 200 is in near fieldrange, the magnetic field (H-field) produced by the RF signal suppliedto the inductive coupler 462, is inductively coupled to the coupler 163of the first NFC communicator 200 (in FIG. 4 M denotes the mutualinductance between the two inductors of the inductive couplers 462 and163). The near field range, that is the range or distance over whichinductive coupling arises between the couplers 462 and 163, will dependon the apparatus involved, in particular the antenna design and positionof antenna. Ranges of up to several centimetres are common for NFCcommunications enabled devices.

In the manner described above and with reference to FIG. 3, the powerderiver 164 derives power from the inductively coupled RF signaltransmitted by the second NFC communicator 400. Thus, the RF signalinductively coupled to the coupler 163 is converted by the rectifier 154to a DC signal 160 which is in turn converted via the charging unit 157into an appropriate charging signal 161 to charge the chargeable powersupply 159.

In FIG. 4 the NFC communicator 200 receives power and the other nearfield RF communicator 400 provides or transfers power. However, as willbe appreciated, an NFC communicator or NFC communications enabled deviceembodying the invention may comprise both the ability to receive powerand the ability to transfer power and, for example, whether an NFCcommunicator or NFC communications enabled device is operable to deriveor provide power may depend upon the particular circumstances (forexample the relative levels of available power) or particularconfigurations or modes of operation of the two communicators or deviceswhen they come into near field range of one another.

As described above, power derivation may occur in a variety of ways ormodes of operation and may occur during or independently of datacommunication between the NFC communicators. A number of examples ofways in which power may be derived will now be described. It shouldhowever be appreciated that these are only examples.

In one example, a first, power requiring NFC communicator or NFCcommunications enabled device such as the first NFC communicator 200shown in FIG. 4 may derive power from a second, power providing NFCcommunicator or NFC communications enabled device such as the secondnear field RF communicator 400 shown in FIG. 4 when data is not beingcommunicated. In this example, the second near field RF communicator ornear field RF communications enabled device is operable to generate anun-modulated RF field from which an in-range NFC communicator or NFCcommunications enabled device embodying the invention may derive powerto charge a chargeable power supply. The second, power providing nearfield RF communicator or near field RF communications enabled device maybe operable to generate the un-modulated RF field in response to receiptof a request from the first, power requiring NFC communicator or NFCcommunications enabled device and/or may be operable to generate theun-modulated RF field automatically at certain times or intervals, forexample immediately following communication of data. In this example,the controller (see FIG. 3) may be configured to activate its powerderiver in response to detection of an un-modulated RF field so as, asdiscussed above with reference to FIG. 3, to derive a power supply fromthe un-modulated RF signal supplied by the second near field RFcommunicator or near field RF communications enabled device.Alternatively the power deriver may be activated when battery power islow by, for example user intervention or following data communication orinitially at the start of data communication to ensure sufficient poweris stored to carry out the necessary data communication. The derivedpower may be used directly to power components of the first NFCcommunicator or NFC communication enabled device (and possibly of anyhost device) and/or to charge or recharge its chargeable power supply.

In another example where a first, power requiring NFC communicator orNFC communications enabled device such as the first NFC communicator 200shown in FIG. 4 may derive power from a second, power providing nearfield RF communicator or near field RF communications enabled devicesuch as the NFC communicator 400 shown in FIG. 4, the second near fieldRF communicator or near field RF communications enabled device maytransmit a different RF frequency for power derivation than for datacommunication and the NFC operational components of the first, powerrequiring NFC communicator or NFC communications enabled device maycomprise a frequency detector and be operable to switch to a powerderivation mode in which the power deriver is activated when thatdifferent RF frequency is detected. In this example, communication ofdata occurs independently from communication of power.

In another example where a first, power requiring NFC communicator orNFC communications enabled device such as the first NFC communicator 200shown in FIG. 4 may derive power from a second, power providing nearfield RF communicator or near field RF communications enabled devicesuch as the second NFC communicator 400 shown in FIG. 4, communicationof power and data may be simultaneous and utilize the same RF field. Insuch circumstances the power deriver will be activated to enablecharging of the chargeable power supply following receipt of an RF fieldby the first NFC communicator or NFC communication enabled device.Multiple inductive couplers may be included within the first NFCcommunicator or NFC communications enabled device to maximize transferof power. Such simultaneous power transfer may also assist to minimizeor control power usage within the NFC communicator or NFC communicationsenabled device. Where power transfer occurs alongside communication ofdata or directly following such communication, the chargeable powersupply within the NFC communicator or NFC communications enabled devicemay be topped up during or shortly after data communication so as toavoid drain of power supply, particularly of any host device. This maybe particularly advantageous where a large amount of data needs to betransferred. For example where as in FIG. 1 the NFC communicationsenabled devices comprise a mobile telephone arid a portable computersuch as a laptop, the power supply within the portable computer can beused to replenish the chargeable power supply of the mobile telephoneafter use, to prevent the mobile telephone battery being drained.

Where power transfer occurs simultaneously with data communication ordirectly following data communication, the controller of the first,power requiring NFC communicator or NFC communications enabled devicemay maximize RF field availability for power transfer either byprolonging data communication with the second, power providing nearfield RF communicator or near field RF communication enabled device orby instructing the second, power providing near field RF communicator ornear field RF communications enabled device to maintain its RF field.Further data communication (in the form of data to be stored and/orinstructions) may follow once sufficient power transfer has occurred.

In another example where a first, power requiring NFC communicator orNFC communications enabled device such as the first NFC communicator 200shown in FIG. 4 may derive power from a second, power providing nearfield RF communicator or near field RF communications enabled devicesuch as the second NFC communicator 400 shown in FIG. 4, power transfermay be brought about or maximized through a change in normal operationof the second, power providing near field RF communicator or near fieldRF communications enabled device. Thus, where the second, powerproviding near field RF communicator or near field RF communicationsenabled device is or comprises an NFC communicator similar to thatdescribed in FIG. 3 and is operating in target mode, communication withthe first power requiring NFC communicator or NEC communications enableddevice may cause the second near field RF communicator or near field REcommunications enabled device to switch from target mode to initiatormode, thereby permitting the first NFC communicator or NFCcommunications enabled device to derive a power supply from a suppliedRF signal. Where the second near field RF communicator is operating asan initiator but in accordance with the active protocol, communicationwith the first power requiring NFC communications enabled device maycause the second near field RF communicator to switch to the passiveprotocol thereby supplying a constant RF field from which the secondnear field RF communicator can derive a power supply.

A power requiring NFC communicator may also request another NFCcommunicator to change from target to initiator mode (and vice versa) sothat the power requiring NFC communicator may derive a power supply froman R F signal generated by the other NFC communicator.

Also, an NFC communicator or communications enabled device may issue (bymodulating an RF signal) a request for power transfer automatically, forexample where the relevant power supply is close to exhaustion.

Thus, there is a number of ways in which power derivation may becontrolled, for example, power may be derived, automatically before,during or after data communication or upon user instruction or only uponagreement between the two NFC communicators or NFC communicationsenabled devices, for example a controller of one of the twocommunicators or devices may request, if the controller determines thatits chargeable power supply needs charging, an opportunity to derivepower when in communication with the other NFC communicator or NFCcommunications enabled device and may activate power derivation inresponse to acceptance of the request, As another possibility, an NFCcommunicator or NFC communications enabled device may transmit an RFsignal that indicates (for example is un-modulated or is modulated in acertain way) to another NFC communicator or NFC communications enableddevice in near field range the availability of a RF signal for use inpower derivation.

As described above, a first, power requiring NFC communicator or NFCcommunications enabled device may operate in a data communication modeand a power derivation mode. A second, power providing near field RFcommunicator or near field RF communications enabled device maysimilarly have a data communication mode and a power supply mode.Depending upon their functionality, either or both of the communicatorsor communications enabled devices may also have a third mode, a powerderivation mode for the second near field RF communicator or near fieldRF communications enabled device and a power supply mode for the firstNFC communicator or NFC communications enabled device. The mode ofoperation of an NFC communicator or near field RF communicator will bedetermined by a controller controlling operation of the NFC communicatoror near field RF communicator and a mode change may be as a result ofuser intervention, on completion of any data communication (that is whenno other data communication is occurring) on receipt of a request forpower transfer from another near field RF communicator or near field RFcommunications enabled device or on detection of another near field RFcommunicator or near field RF communications enabled device. In powertransfer mode, an near field RF communicator controller may instructswitching functions within the near field RF communicator to change thegenerated signal properties and/or circuit configuration to facilitateand maximize power transfer. Also, during power transfer, the powerproviding near field RF communicator may suspend data communication orprocessing of received data in order to maximize the power beingtransferred and therefore the replenishment of the chargeable powersupply of the other power deriving near field RF communicator or nearfield RF communications enabled device.

As described above, an NFC communicator or NFC communications enableddevice embodying the invention uses the same coupler or couplers fordata communication and power derivation. This need not necessarily bethe case and separate couplers may be used for data communication andpower derivation by either one or both of two communicators orcommunications enabled devices.

FIG. 5 shows a functional block diagram of an NFC communicator 600having separate couplers for data communication and power derivation.Although not shown in FIG. 5, the NFC communicator 600 may or may not beassociated with at least one of further functionality (that is it mayform part of or be attached or associated with a host device) and a userinterface.

The NFC communicator 600 shown in FIG. 5 comprises NFC operationalcomponents 101 a which, like the NFC operational components 101 shown inFIG. 2, comprise a controller 107 a for controlling overall operation ofthe NFC communicator coupled to a data store 108 for storing data to betransmitted from and/or data received by the NFC communicator; ademodulator 114 coupled between the coupler 102 and the controller 107for demodulating a modulated signal inductively coupled to the couplerfrom another NFC communicator or NFC communications enabled device innear field range; a signal generator 109 for generating an RF signal, amodulator 110 for modulating an RF signal and a driver for driving acoupler 506 in accordance with the output of the modulator 110. Thecoupler 506 comprises an antenna coil or inductor 307 possiblyassociated, in the manner described above, with one or more capacitors352. Although not shown in FIG. 5, the NFC communicator 600 may also becapable of interference or simulated load modulation in accordance withWO2005/045744. As thus far described, the NFC communicator 600 issimilar to that shown in FIG. 3 and functions in similar manner. Likethe NFC communicator shown in FIG. 3, the NFC communicator 600 also hasa power deriver 164 (comprising, as shown a rectifier 154 and a chargingcircuit 157 which may be as described above) coupled to a chargeablepower supply 159 which may be provided within or attached to the NFCcommunicator 600 or provided within or attached to another deviceassociated with or incorporating the NFC communicator. However, in thisexample, the power deriver 157 is not coupled to the coupler 506 but iscoupled to a separate coupler 505 again comprising an antenna in theform of a coil or inductor possibly associated, in the manner describedabove, with one or more capacitors.

The controller 107 a is configured to control both the operation of theNFC operational components 101 a and the power deriver 164 and inoperation will control whether the coupler 506 or the power deriver 164together with inductive coupler 505 is operable on receipt of anexternally supplied RF signal (represented as arrows 500 and 501). In apreferred embodiment the controller 107 a is operable to turn off thepower deriver 164 until a set time or set series of instructions isreceived from an near field RF communicator or near field RFcommunications enabled device. For example on receipt of a modulated RFsignal from another near field RF communicator or near field RFcommunications enabled device (not shown), the received modulated signalmay be demodulated by demodulator 114 and interpreted by controller 107a. Depending on the data received, the controller 107 a may then cause amodulated RF signal modulated in accordance with the appropriateoperating protocol and data stored in the data store 108 to betransmitted for receipt by the other near field RF communicator or nearfield RF communications enabled device. Following completion of datacommunication between the two communicators or communications enableddevices, the controller 107 a may then turn on the power deriver 164 andinductive coupler 505 or control switches in the paths from the twocouplers so that the coupler 506 is disconnected from the NFCcommunicator 100 a and the coupler 505 is connected to the power deriverso that an RF field generated by the other near field RF communicator ornear field RF communications enabled device can then be used forcharging purposes.

Alternatively both the power deriver 164 and the NFC operationalcomponents 101 a shown in FIG. 5 may be operable at the same time and inresponse to the same RF field. The couplers may be configured usingappropriate filter arrangements so that one is responsive to onefrequency and the other to another frequency RF field with the differentfrequency fields being generated by the same or different NFCcommunications enabled devices. As in the other examples describedabove, the NFC communicator 600 shown in FIG. 5 may be a standalone NFCcommunicator or may be embodied in or associated with a host device.Where the NFC communicator is comprised within a host device, thecontroller 107 a may interface with a controller of the host device andoptionally the host device controller may control whether the NFCcommunicator is in a power derivation mode or a data communication modeor both.

The use of different frequencies for the two couplers 506 and 505 mayminimize interference between the inductive couplers. Alternatively oradditionally, the antennas 352 and 152 may be physically separated ororientated such that their axes are 90 degrees apart so that theyrespond to correspondingly orientated H fields.

A number of applications for NFC communicators and NFC communicationsenabled devices will now be described with the aid of FIGS. 6 to 9.

FIG. 6 shows a simplified view of two NFC communications enabled devices700 and 800 communicating. In this example, one NFC communicationsenabled device 700 comprises a mobile telephone having the usual mobiletelephone features including a mobile telephone chargeable battery 701and an NFC communicator 702 having the features described above withreference to any of FIGS. 1 to 5 and, as shown an emergency chargeablepower supply or battery 703 which may be attachable to and detachablefrom the mobile telephone. As shown by the solid double arrows in FIG.6, the NFC communicator 702 is coupled to both the mobile telephonechargeable battery 701 and the emergency chargeable power supply orbattery 703.

In this example, the other NFC communications enabled device 800comprises an electrical device which may be any suitable electricaldevice such as a portable electrical device, a desk top electricaldevice or other item of office or home electrical equipment and so on.For example, the other NFC communications enabled device 800 may be alaptop or notebook computer or a computer peripheral such as a printeror keyboard. In addition to its normal functionality (not illustrated inFIG. 6) and a power supply 801 which may be a mains or battery powersupply, the other NFC communications enabled device 800 has an NFCcommunicator as described above coupled to derive power from the powersupply 801. In the alternative the RF field from which the power isderived may be supplied by an RF communicator (whether stand-alone orcomprised within a host device).

In the scenario shown in FIG. 6 when, for example, either the mobiletelephone functionality or the user determines that the battery is low,then the user (possibly after prompting by the mobile telephone) bringsthe mobile telephone 700 into near field range of the other NFCcommunications enabled device 800 and (possibly only after the user hasconfirmed that the NFC communications enabled devices are in near fieldrange using the key pad 705), the NFC communicator 702 issues (bymodulating an RF signal) a request for power transfer to any NFCcommunications enabled device in near field range. As anotherpossibility, the NFC communicator 702 may be periodically activated tocheck for any in-range NFC communications enabled devices and may causea controller of the mobile telephone to display on the display 704 amessage to the user asking whether power transfer is required, wheneverthere is a power providing NFC communications enabled device in nearfield range. Then, if the user selects power transfer using the keypad705, the mobile telephone controller will instruct the NFC communicator702 to issue (by modulating an RF signal) a request for power transferto any NFC communications enabled device in near field range.

Once communication between the two NFC communications enabled deviceshas been established, then the NFC communicator 702 may derive powerfrom an RF signal supplied by the NFC communicator 802 in any of theways described above.

Alternatively the user may control the operation of NFC communicationsdevice 800 such that it is automatically in ‘power providing’ mode andconstantly transmitting an RF signal. When the user brings NFCcommunications enabled device 700 into the near field range of device800, the NFC communicator within mobile phone 700 automatically derivespower from the supplied RF signal and uses the derived power to top-upthe mobile phone battery or to trickle charge some alternative oradditional power supply.

The NFC communicator 702 may additionally (or alternatively) charge upor trickle charge the emergency battery 703 for later use with themobile telephone or other compatible device.

In addition in FIG. 6, data may be communicated by NFC communicationbetween the NFC communicators of the two devices so that, for example,data (such as for example personal organizer data, music data, videodata and so on) may be transferred between the portable computer andmobile telephone.

FIG. 7 shows another scenario in which the NFC communications enabledmobile telephone 700 is in near field range of two NFC communicationsenabled devices, a portable computer (laptop or notebook computer) 803and a printer 900 which will generally, although not shown, be mainspowered. In this case, as shown by the dashed lines, the mobiletelephone NFC communicator 702 may derive power for itself and/or themobile telephone as discussed above from near field RF signalstransmitted by either the portable computer NFC communicator 804 or theprinter NFC communicator 902 or a combination of both. Also although notshown in FIG. 7, the portable computer NFC communicator 802 may derivepower for itself and/or the portable computer from the near field RFsignal transmitted by the printer NFC communicator 902. In addition,data may be communicated by NFC communication between the NFCcommunicators 702, 804 and 902 of the three devices so that, forexample, data stored by the portable computer or mobile telephone may besupplied to the printer for printing by NFC communication and data (suchas for example personal organizer data, music data, video data and soon) may be transferred between the portable computer and mobiletelephone.

FIGS. 8 and 9 illustrate another scenario in the form of an accesssystem in which an NFC communications enabled mobile telephone 700 (orother portable electrical device such as a PDA) is programmed withticket or access pass software for enabling the user to obtain anelectronic ticket, access pass or authorization code such that, when theNFC communicator (not shown in FIG. 8) of the mobile telephone 700 is innear field communication with an NFC communicator 1001 of an access gate1000 responsive to that electronic ticket, access pass or authorizationcode, access will be granted to the user (u) of that mobile telephone.

FIG. 9 shows a flow chart for explaining the functioning of such anaccess system.

Thus at S1, in response to user input via the keypad, the mobiletelephone 700 obtains an electronic ticket, access pass or authorizationcode for the access gate, as shown in FIG. 9 by the user purchasing atrain ticket. As shown at S2, the electronic ticket, access pass orauthorization code may be obtained by NFC communication with, forexample, an automatic ticket dispenser comprising an NFC communicationsenabled device embodying the invention which may also be used, asdescribed above, to power or charge up the mobile telephone, for examplewhile the users payment is being cleared by communications between theticket dispenser and a transactions house in the same manner as would beused for a credit transaction. As another possibility, the electronicticket, access pass or authorization code for the access gate may bepurchased over the mobile telecommunications network or by the user froma ticket kiosk in which case the user will need to enter the electronicticket, access pass or authorization code provided by the human ticketvendor into the mobile telephone—using its keypad.

Once the electronic ticket, access pass or authorization code is storedin the mobile telephone at S3 the mobile telephone 700 is programmed tofunction as the electronic ticket, access pass or authorization codeprovider.

CONCLUSION

The user then brings at S5 the mobile telephone into near fieldcommunication range of the NFC communicator 1001 of the access gate 1000and, at S7, the NFC communicator of the mobile telephone communicateswith the NFC communicator 1001 of the access gate to transfer , datarepresenting the electronic ticket, access pass or authorization code.Such data may be encrypted or provided in protected format. At S8, theNFC communicator 1001 of the access gate 1000 receives the transferreddata and it or a controller of the access gate checks the authenticityand correctness of the transferred data and, if it is authentic andcorrect, allows the user of the mobile telephone access through theaccess gate 1000.

It will of course be appreciated that the power deriver shown in FIG. 3is only one possible example of a suitable power deriver and othercircuit configurations may be advantageous in order to further maximizepower transfer efficiencies.

The chargeable power supply may be the sole power supply of the NFCcommunications enabled device or alternatively may be one of a number ofpower supplies comprised within the NFC communications enabled device.For example, the NFC enabled device may have a separate power supply andthe chargeable power supply may be used simply as a back-up in the eventthat power supply fails. In this case, the chargeable power supply maybe incorporated within the NFC communicator or within the host devicewhere the NFC communications enabled device has functionality beyond theNFC communicator functionality or may be provided as a separate powersupply device couplable to the NFC communications enabled device. Asanother possibility or additionally, where the NFC communicationsenabled device has functionality beyond the NFC communicatorfunctionality, the NFC communicator and host device may have separatepower supplies that may be chargeable by the power deriver eitherdirectly or from a charged chargeable power supply itself chargeddirectly by the power deriver. The power deriver may also be coupled andconfigured to trickle-charge or replenish a second power storage device.For example an available RF field may be used to re-charge a lap-topbattery or mobile telephone battery. Additional circuitry may beincluded to selectively feed alternative DC and AC power sources to theinput of the charging circuit or to the input of the rectifier,respectively, for example. A mains power-adapter is an examplealternative DC power source.

In examples given above, both the power requirer and the power providerare NFC communicators or NFC communications enabled devices. In exampleswhere the power provider has to be capable of initiating near fieldcommunication but does not have to be capable of responding toinitiation of near field communication by the power requirer, then thepower provider may be an initiating near field communicator such as anRFID transceiver or reader. In examples where the power provider has tobe capable of responding to initiation of near field communication bythe power requirer but does not have to be capable of initiating nearfield communication, then the power provider may be a responding nearfield communicator such as an RFID transponder or tag, if sufficientpower can be provided. An NFC communicator may operate in accordancewith ISO/IEC 18092 and/or ISO/IEC 21481 while an RFID reader or RFID tagmay operate fully or partially in accordance with RFID ISO/IEC 14443A orISO/IEC 15693.

It is to be understood that any feature described in relation to any oneembodiment may be used alone, or in combination with other featuresdescribed, and may also be used in combination with one or more featuresof any other of the embodiments, or any combination of any other of theembodiments. Furthermore, equivalents and modifications not describedabove may also be employed without departing from the scope of theinvention, which is defined in the accompanying claims.

What is claimed is:
 1. A Near Field Communications (NFC) enabled device,comprising: an NFC component module configured to communicate withanother NFC enabled device via inductive coupling utilizing a data path;a power deriver module configured to rectify an induced power receivedfrom the other NFC enabled device to provide a rectified power, therectified power conditionally charging a chargeable power supplyutilizing a power path; and a controller module configured to enable thepower deriver module to charge the chargeable power supply upondetection of an unmodulated communications signal received from theother NFC enabled device; wherein the data path and the power path areseparate paths.
 2. The NFC enabled device of claim 1, wherein the powerpath and the data path terminate in a connection to a common couplingdevice, wherein the NFC component module is farther configured tocommunicate with the other NFC enabled device using the common couplingdevice, and wherein the power deriver module is further configured toreceive the induced power using the common coupling device.
 3. The NFCdevice of claim 1, wherein the power path and the data path terminate ina connection to a first and a second coupling device, respectively,wherein the NFC component module is farther configured to communicatewith the other NFC enabled device using the first coupling device, andwherein the power deriver module is further configured to receive theinduced power using the second coupling device.
 4. The NFC enableddevice of claim 2, wherein the common coupling device includes aninductor and a capacitor connected in parallel with one another.
 5. TheNFC enabled device of claim 2, wherein the power deriver comprises: abridge rectifier coupled to the common coupling device.
 6. The NFCenabled device of claim 1, wherein the NFC component module is furtherconfigured to utilize power from the chargeable power supply or therectified power.
 7. The NFC enabled device of claim 1, wherein the NFCcomponent module utilizes the chargeable power supply to communicatewith the other NFC enabled device; and wherein the controller is furtherconfigured to enable the power deriver module to charge the chargeablepower supply when the chargeable power supply cannot provide sufficientpower to the NFC component module.
 8. A Near Field Communications (NFC)enabled device, comprising: an NFC component module configured tocommunicate via inductive coupling with another NFC enabled deviceutilizing a first carrier frequency when the NFC enabled device isoperating in a communications mode; a power deriver module configured tocharge a chargeable power supply utilizing a second carrier frequencywhen the NFC enabled device is operating in a power derivation mode; anda frequency detector module configured to switch operation of the NFCenabled device between the communications mode and the power derivationmode based on whether a detected carrier frequency received from theother NFC enabled device is substantially equal to the first carrierfrequency or the second carrier frequency; wherein the NFC componentmodule is further configured to communicate with the other NFC enableddevice utilizing a data path, and wherein the power deriver module isfurther configured to charge the chargeable power supply utilizing apower path, the data path and the power path being separate paths. 9.The NFC enabled device of claim 8, wherein the NFC component module isfurther configured to disable communications with the other NFC enableddevice when the NFC enabled device is operating in the power derivationmode; and wherein the power deriver module is further configured todisable charging when the NFC enabled device is operating in thecommunications mode.
 10. The NFC enabled device of claim 8, wherein thepower path and the data path terminate in a connection to a commoncoupling device, wherein the NFC component module is further configuredto communicate with the other NFC enabled device using the commoncoupling device, and wherein the power deriver module is furtherconfigured to receive the second carrier frequency using the commoncoupling device.
 11. The NFC device of claim 8, wherein the power pathand the data path terminate in a connection to a first and a secondcoupling device, respectively, wherein the NFC component module isfurther configured to communicate with the other NFC enabled deviceusing the first coupling device, and wherein the power deriver module isfurther configured to receive the second carrier frequency using thesecond coupling device.
 12. The NFC enabled device of claim 10, whereinthe common coupling device includes an inductor and a capacitorconnected in parallel with one another.
 13. The NFC enabled device ofclaim 10, wherein the power deriver comprises: a bridge rectifiercoupled to the common coupling device.
 14. The NFC enabled device ofclaim 9, wherein the NFC component module is further configured toutilize power from the chargeable power supply or the rectified power.15. A Near Field Communications (NFC) enabled device, comprising: an NFCcomponent module configured to communicate via inductive coupling withanother NFC enabled device in accordance with one of an initiator or atarget mode of operation; a power deriver module configured to charge achargeable power supply when the NFC enabled device is operating in thetarget mode; and a controller module configured to switch operation ofthe NFC enabled device from the initiator mode to the target mode basedon a charge requirement of the chargeable power supply; wherein the NFCcomponent module is further configured to communicate with the other NFCenabled device utilizing a data path; and wherein the power derivermodule is further configured to charge the chargeable power supplyutilizing a power path substantially simultaneously with communicationsbetween the NFC component module and the other NFC enabled device, thedata path and the power path being separate paths.
 16. The NFC enableddevice of claim 15, wherein the power path and the data path terminatein a connection to a common coupling device, wherein the NFC componentmodule is further configured to communicate with the other NFC enableddevice using the common coupling device, and wherein the power derivermodule is further configured to charge the chargeable power supply usingthe common coupling device.
 17. The NFC device of claim 15, wherein thepower path and the data path terminate in a connection to a first and asecond coupling device, respectively, wherein the NFC component moduleis further configured to communicate with the other NFC enabled deviceusing the first coupling device, and wherein the power deriver module isfurther configured to charge the chargeable power supply using thesecond coupling device.
 18. The NFC enabled device of claim 16, whereinthe common coupling device includes an inductor and a capacitorconnected in parallel with one another.
 19. The NFC enabled device ofclaim 16, wherein the power deliver comprises: a bridge rectifiercoupled to the coupling device.
 20. The NFC enabled device of claim 15,wherein the NFC component module is further configured to utilize powerfrom the chargeable power supply or the rectified power.